OpenFlow debuts on an optical network

SAN JOSE – The move to software-defined networks passed another milestone as ADVA Optical Networking (Munich) demonstrated the OpenFlow specification for the first time on an optically switched network. The demo is part of Europe’s OFELIA project and is now available for use as a test bed for researchers.

OpenFlow is a specification that emerged from work at Stanford to implement network virtualization and control in software. Google, one of the main proponents of the technology, recently revealed its efforts using OpenFlow on one of its electrically switched production networks.

Software-defined networking aims to simplify the configuration and management of large networks. Today’s nets use an increasingly complex set of specialized systems and protocols that require significant expertise to manage, creating difficulties especially in fast-growing Web 2.0 data centers.

ADVA’s work was a collaboration between a handful of its engineers and PhD candidates at the University of Essex where the test bed is based. The team needed to create several extensions to OpenFlow including a hardware abstraction layer for optical nets which currently is not part of the specification.

“OpenFlow is not yet mature enough nor does it have the features to cope with all the aspects of an optical network,” said Achim Autenrieth, a principal engineer at ADVA.

“A lot of OpenFlow comes from Ethernet people who don’t know much about the needs of optical networks,” said Stephan Rettenberger, vice president of global marketing at ADVA.

The demo uses ADVA’s FSP 3000 wavelength division multiplexing switch and its RayControl management software. All the OpenFlow work was handled in software with no changes to hardware.

Engineers will develop a network virtualization app as a next step for the test bed. They also plan to “open up and make visible to the OpenFlow controller more optical functions [such as] realizing signal impairment-aware routing services,” said Autenrieth.

Researchers in Brazil, Europe, Japan and the U.S. can access the OpenFlow island on the OFELIA network through GÉANT, a pan-European backbone that connects national research nets. The OFELIA project is scheduled to remain live for about a year.

The demo is being shown this week at the European Future Internet Assembly in Aalborn, Denmark.

If the demo sparks demand, ADVA will develop commercial OpenFlow software for its systems, a project which will take considerably more effort than the research demo and has not yet started, Autenrieth said. So far, there is no active work on an optical abstraction layer in the OpenFlow standards group, he added.

Data centers likely will be the first movers into OpenFlow. Telco networks are more mature and relatively slow to make operational changes, said Rettenberger. Nevertheless SDN is clearly the future for all networks, and OpenFlow is gaining momentum as one route in that direction, he added.

Optical nets “are just entering a phase where with software we can change modulation schemes, and the more flexible and automated the nets become, the better,” Rettenberger said. “OpenFlow would be an attractive means to control the optical network, it’s not the only tool but the data center guys love it,” he said.

“SDN presents a tremendous opportunity for customers to streamline and automatenetwork infrastructure and operations,” said Christoph Glingener, chief technology officer of ADVA, speaking in a press statement.

“While server and storage virtualization have been widely adopted, network virtualization is still in its infancy,” he said. “SDN closes this gap by offering programmable network control, better scalability and faster adaption to virtual machine mobility,” he added.

“Together we have built an SDN testbed with packet and wavelength switches under a common OpenFlow control--something that has never been done before,” said Dimitra Simeonidou, head of the High Performance Networks Group and a professor at the University of Essex.

At Interop, Vello demonstrated a use case for SDN involving a Vello SDN controller using OpenFlow to "talk to" optical systems as well as packet switches. This application, Remote Data Replication Manager, offers a practical solution for data replication of value to enterprises today, and unlike much of the talk about SDN, enterprise customers can see the value of this immediately. Visit Vello at EMC World, or learn more here: http://www.vellosystems.com/_pdf/Vello_Uses_SDN_to_Enable_Remote_Data_Replication_as_a_Service_050812.pdf